Cleft lip and palate (CLP) is one of the most common craniofacial malformations. Overall, 40-80% of CLP patients have varying degrees of articulation problems after palatoplasty. Previous studies revealed abnormal articulation-related brain function in CLP patients. However, the association between articulation disorders and cortical structure development in CLP patients remains unclear. Twenty-six CLP adolescents (aged 5-14 years; mean 8.88 years; female/male 8/18), twenty-three CLP adults (aged 18-35 years; mean 23.35 years; female/male 6/17), thirty-seven healthy adolescents (aged 5-16 years; mean 9.89 years; female/male 5/16), and twenty-two healthy adults (aged 19-37 years; mean 24.41 years; female/male 19/37) took part in the experiment. The current study aims to investigate developmental changes in cortical structures in CLP patients with articulation disorders using both structural and functional magnetic resonance imaging (MRI). Our results reveal the distinct distribution of abnormal cortical structures in adolescent and adult CLP patients. We also found that the developmental pattern of cortical structures in CLP patients differed from the pattern in healthy controls (delayed cortical development in the left lingual gyrus (t = 4.02, cluster-wise p < 0.05), inferior temporal cortex (z = -4.36, cluster-wise p < 0.05) and right precentral cortex (t = 4.19, cluster-wise p < 0.05)). Mediation analysis identified the cortical thickness of the left pericalcarine cortex as the mediator between age and articulation function (partial mediation effect (a*b = -0.48), 95% confident interval (-0.75, -0.26)). In conclusion, our results demonstrate an abnormal developmental pattern of cortical structures in CLP patients, which is directly related to their articulation disorders.
Keywords: articulation disorder; cleft lip and palate; cortical development; mediation effect.